[Why & How]
Revert commit 8b2cb32cf0c6
("drm/amd/display: FEC overhead should be checked once for mst slot nums")
Because causes bw calculation regression
Cc: mario.limonciello@xxxxxxx
Cc: alexander.deucher@xxxxxxx
Reported-by: jirislaby@xxxxxxxxxx
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3495
Closes: https://bugzilla.suse.com/show_bug.cgi?id=1228093
Reviewed-by: Wayne Lin <wayne.lin@xxxxxxx>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
Signed-off-by: Tom Chung <chiahsuan.chung@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
(cherry picked from commit 12dbb3ed212fc7655fce421542a5add637f8af7a)
Cc: stable@xxxxxxxxxxxxxxx
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 915eb2c08ece..2e9f6da1acdc 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -804,12 +804,25 @@ struct dsc_mst_fairness_params {
};
#if defined(CONFIG_DRM_AMD_DC_FP)
-static int kbps_to_peak_pbn(int kbps)
+static uint16_t get_fec_overhead_multiplier(struct dc_link *dc_link)
+{
+ u8 link_coding_cap;
+ uint16_t fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_8B_10B;
+
+ link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(dc_link);
+ if (link_coding_cap == DP_128b_132b_ENCODING)
+ fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_128B_132B;
+
+ return fec_overhead_multiplier_x1000;
+}
+
+static int kbps_to_peak_pbn(int kbps, uint16_t fec_overhead_multiplier_x1000)
{
u64 peak_kbps = kbps;
peak_kbps *= 1006;
- peak_kbps = div_u64(peak_kbps, 1000);
+ peak_kbps *= fec_overhead_multiplier_x1000;
+ peak_kbps = div_u64(peak_kbps, 1000 * 1000);
return (int) DIV64_U64_ROUND_UP(peak_kbps * 64, (54 * 8 * 1000));
}
@@ -910,11 +923,12 @@ static int increase_dsc_bpp(struct drm_atomic_state *state,
int link_timeslots_used;
int fair_pbn_alloc;
int ret = 0;
+ uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
for (i = 0; i < count; i++) {
if (vars[i + k].dsc_enabled) {
initial_slack[i] =
- kbps_to_peak_pbn(params[i].bw_range.max_kbps) - vars[i + k].pbn;
+ kbps_to_peak_pbn(params[i].bw_range.max_kbps, fec_overhead_multiplier_x1000) - vars[i + k].pbn;
bpp_increased[i] = false;
remaining_to_increase += 1;
} else {
@@ -1010,6 +1024,7 @@ static int try_disable_dsc(struct drm_atomic_state *state,
int next_index;
int remaining_to_try = 0;
int ret;
+ uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
for (i = 0; i < count; i++) {
if (vars[i + k].dsc_enabled
@@ -1039,7 +1054,7 @@ static int try_disable_dsc(struct drm_atomic_state *state,
if (next_index == -1)
break;
- vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps);
+ vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
ret = drm_dp_atomic_find_time_slots(state,
params[next_index].port->mgr,
params[next_index].port,
@@ -1052,8 +1067,7 @@ static int try_disable_dsc(struct drm_atomic_state *state,
vars[next_index].dsc_enabled = false;
vars[next_index].bpp_x16 = 0;
} else {
- vars[next_index].pbn = kbps_to_peak_pbn(
- params[next_index].bw_range.max_kbps);
+ vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
ret = drm_dp_atomic_find_time_slots(state,
params[next_index].port->mgr,
params[next_index].port,
@@ -1082,6 +1096,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
int count = 0;
int i, k, ret;
bool debugfs_overwrite = false;
+ uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
memset(params, 0, sizeof(params));
@@ -1146,7 +1161,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
/* Try no compression */
for (i = 0; i < count; i++) {
vars[i + k].aconnector = params[i].aconnector;
- vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
+ vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
vars[i + k].dsc_enabled = false;
vars[i + k].bpp_x16 = 0;
ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr, params[i].port,
@@ -1165,7 +1180,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
/* Try max compression */
for (i = 0; i < count; i++) {
if (params[i].compression_possible && params[i].clock_force_enable != DSC_CLK_FORCE_DISABLE) {
- vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.min_kbps);
+ vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.min_kbps, fec_overhead_multiplier_x1000);
vars[i + k].dsc_enabled = true;
vars[i + k].bpp_x16 = params[i].bw_range.min_target_bpp_x16;
ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
@@ -1173,7 +1188,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
if (ret < 0)
return ret;
} else {
- vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
+ vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
vars[i + k].dsc_enabled = false;
vars[i + k].bpp_x16 = 0;
ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
index fa84d34b7373..600d6e221011 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
@@ -46,6 +46,9 @@
#define SYNAPTICS_CASCADED_HUB_ID 0x5A
#define IS_SYNAPTICS_CASCADED_PANAMERA(devName, data) ((IS_SYNAPTICS_PANAMERA(devName) && ((int)data[2] == SYNAPTICS_CASCADED_HUB_ID)) ? 1 : 0)
+#define PBN_FEC_OVERHEAD_MULTIPLIER_8B_10B 1031
+#define PBN_FEC_OVERHEAD_MULTIPLIER_128B_132B 1000
+
enum mst_msg_ready_type {
NONE_MSG_RDY_EVENT = 0,
DOWN_REP_MSG_RDY_EVENT = 1,
